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Figure 1 | Cancer Cell International

Figure 1

From: Role of IGF-1/IGF-1R in regulation of invasion in DU145 prostate cancer cells

Figure 1

IGF-1 stimulates the in vitro invasion of DU145 cells through the IGF-1R, via both the PI3-K and MAPK pathways. A) Representative experiment showing number of cells invading a Matrigel-coated membrane relative to surface area. Serum-deprived DU145 cells were treated for 24 hours with indicated concentrations of IGF-1 after which 5 × 104 cells were allowed to invade through the Matrigel for 24 hours. IGF-1 treatment induces a dose-responsive increase in the invasive potential of DU145 cells through Matrigel compared to invasion in mock-treated cells that were administered a volume of 1× PBS similar to the 200 ng/ml condition. (*p < 0.05; Fisher exact T-test). B) Number of cells invading a Matrigel-coated membrane relative to surface area. Serum-deprived DU145 cells were pretreated for 24 hours with a neutralizing IGF-1R antibody (IGF-1Rab), then treated with 200 ng/ml IGF-1 for 24 hours. 5 × 104 cells were allowed to invade through the Matrigel for 24 hours. The increase in Matrigel invasion of DU145 cells stimulated by IGF-1 is significantly decreased in the presence of the IGF-1R neutralizing antibody (*p < 0.05; Fisher exact T-test) The control consisted of adding a similar amount of the vehicle (1× PBS) for each addition in the test conditions. C,D,E,F) Serum-deprived DU145 cells were pre-treated in the presence or absence of the PI3-K inhibitor wortmannin or the MEK inhibitor PD98059 for 1 hour, then treated with 200 ng/ml IGF-1 for 1 hour, maintaining previous inhibitor conditions. The control consisted of adding a similar amount of the vehicle (1× PBS for IGF-1, DMSO for wortmannin or PD98059) for each addition in the test conditions. C) Immunoblotting shows an increase in Akt phosphorylation in DU145 cells treated with IGF-1, but not in the presence of wortmannin. D) Immunoblotting shows an increase in the phosphorylation of p42/44 MAPK in DU145 cells treated with IGF-1, but not in the presence of PD98059. E,F) Representative experiments showing number of cells invading a Matrigel-coated membrane relative to surface area. At the end of the respective treatments, 5 × 104 cells were added to each invasion chamber and allowed to invade through the Matrigel for 24 hours. E) Each condition was performed on three separate occasions. The relative rate of inhibition by wortmannin of the IGF-1 effect on invasion was consistent across experiments, with a mean of 0.79 +/- 0.083. F) Each condition was performed on four separate occasions. The relative rate of inhibition by PD98059 of the IGF-1 effect on invasion was consistent across experiments, with a mean of 0.37 +/- 0.096.

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